Low-Noise Positive- and Negative-Output Charge Pump With Integrated LDO - LM27762

LM27762 (ACTIVE)

Low-Noise Positive- and Negative-Output Charge Pump With Integrated LDO

 

Description

The LM27762 delivers very low-noise positive and negative outputs that are adjustable between ±1.5 V and ±5 V. Input-voltage range is from 2.7 V to 5.5 V, and output current goes up to ±250 mA. With an operating current of only 390 µA and 0.5-µA typical shutdown current, the LM27762 provides ideal performance for power amplifier and DAC bias and other high-current, low-noise negative voltage needs. The device provides a small solution size with few external components.

Negative voltage is generated by a regulated inverting charge pump followed by a low-noise negative LDO. The inverting charge pump of the LM27762 device operates at 2-MHz (typical) switching frequency to reduce output resistance and voltage ripple. Positive voltage is generated from the input by a low-noise positive LDO.

Positive and negative outputs of LM27762 have dedicated enable inputs. These outputs support independent timing for the positive and negative rails for specific system power-sequence needs. Enable inputs can be also shorted together and connected to the input voltage. The LM27762 has an optional Power Good feature.

For all available packages, see the orderable addendum at the end of the data sheet.

Features

  • Generates Low-Noise Adjustable Positive Supply Voltage Between 1.5 V and 5 V and Negative Supply Voltage Between –1.5 V and –5 V
  • Input Voltage Range 2.7 V to 5.5 V
  • ±250-mA Output Current
  • Inverting Charge Pump Followed by Negative LDO
  • 2-MHz Low-Noise Fixed-Frequency Operation
  • 2.5-Ω Inverter Output Impedance, VIN = 5 V
  • Negative LDO Dropout Voltage 30 mV at 100 mA, VOUT = –5 V
  • Positive LDO with 45-mV Dropout Voltage at 100 mA, VOUT = 5 V
  • 390-µA Quiescent Current (Typical)
  • Shutdown Quiescent Current to 0.5 µA (Typical)
  • Current Limit and Thermal Protection
  • Power Good Pin (Active Low)
  • Create a Custom Design Using the LM27762 With the WEBENCH Power Designer

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Parametrics Compare all products in Buck/Boost or Inverting Charge Pump (Inductorless)

 
Topology
Vin (Min) (V)
Vin (Max) (V)
Vout (Min) (V)
Vout (Max) (V)
Iout (Max) (A)
Switching Frequency (Min) (kHz)
Switching Frequency (Max) (kHz)
Iq (Typ) (mA)
Features
Operating Temperature Range (C)
Rating
Package Group
LM27762 LM27761
Buck/Boost
Inverting   
Inverting   
2.7    2.7   
5.5    5.5   
1.5    -1.5   
5    -5.2   
0.25    0.25   
1800    1700   
2200    2300   
0.39    0.37   
Enable
Integrated LDO
Multiple Outputs
Power Good   
Enable
Integrated LDO   
-40 to 85    -40 to 85   
Catalog    Catalog   
WSON    WSON   

WEBENCH® Designer LM27762

  Min   Max Range
Vin1  V 2.70 to 5.50V

Vout1  V 1.50 to 5.00V
Iout1  A ≤ 0.25A

Vout2  V -5.00 to -1.50V
Iout2  A ≤ 0.25A

Ambient Temp  °C ≤ 100°C